This invention relates to aircraft interior equipment, and more particularly, to aircraft ejection seats.
When a pilot or other aircraft occupant ejects from an aircraft moving at high speed, the occupant is subjected to various aerodynamic forces which, if not properly controlled, may lead to injury. One area of concern is the occupant's arms, which can be severely injured if allowed to flail uncontrollably in the windblast.
Various methods and devices have been proposed to restrain an ejection seat occupant's arms to prevent windblast flailing injuries. U.S. Pat. No. 3,074,669 to Bohlin teaches a plurality of tethers attached to the occupant's arms. As the ejection seat is propelled from the aircraft, the tethers draw the occupant's arms inward and restrain them to prevent windblast flailing. Although satisfactory in operation, the restraints taught by Bohlin are “active” in that they require the occupant to attach the tethers upon entering the aircraft. A significant disadvantage of all “active” systems is that they impose additional tasks on crewmembers in order for them to be readied, and may be improperly attached or ignored entirely by the crewmember, rendering them ineffective.
U.S. Pat. No. 4,592,523 to Herndon discloses a “passive” restraint system that includes a plurality of nets that deploy forward and inward to form a curtain surrounding the occupant. The restraint system disclosed in Herndon requires the added complexity of a pyrotechnic actuator to deploy the system and, because it wraps around the occupant, may interfere with the occupant's separation from the ejection seat after deployment.
U.S. Pat. No. 4,081,156 to Ideskar discloses a passive restraint system that includes a plurality of side curtains that deploy forward to form a cage around the occupant. Although the side curtains of Ideskar restrict the occupant's arms from moving outward, they do not prevent the occupant's arms from flailing upward and possibly over the leading edge of the side curtains.
What is needed is a passive restraint system that reliably prevents arm flail injuries without the disadvantages of the prior art passive restraints.